1. Field of the Invention
The present invention relates to a radiation image pickup device, and more particularly to a radiation image pickup device which can be preferably applied for converting a radiation image such as an x-ray image which penetrates an object to be examined such as a human body into an electric image.
2. Related Background Art
As an x-ray image pickup device that converts an x-ray, which is one form of radiation, into an electric signal, there exists a system, in which an image intensifier (I.I.), which converts an x-ray into light, a television camera and a television set are combined together to obtain an x-ray image (I.I.-TV system). The system is designed such that the x-ray input face size of the image intensifier is of a photographable size. The input face provides about a 16-inch view field, at maximum.
The x-ray image, converted into light, is imaged once on an image intensifier output portion. The output image is picked up by the television camera through an optical system and then outputted as an electric image. In this system, the x-ray image can be observed in real-time.
However, such convention systems typically have insufficient resolution. Also, because a photographing device is large in size, as compared with film, the location of the photographing device is limited, the movement of the system is limited, and so on.
The present invention has been made in view of the above circumstances, and therefore an object of the present invention is to provide a radiation image pickup device which is capable of preferably employing the x-ray image pickup device.
Another object of the present invention is to provide a radiation image pickup device that has excellent sensitivity to incident radiation.
Still another object of the present invention is to provide a radiation image pickup device which is capable of preventing carrier over-flow through a switch even if an excessive input is made.
Still another object of the present invention is to provide a radiation image pickup device which is capable of reducing a residual image and conducting an electrical conversion of stable image information.
Yet still another object of the present invention is to provide a radiation image pickup device which is capable of making the sensitivity higher.
In order to achieve the above objects, according to the present invention, there is provided a radiation image pickup device, comprising:
a plurality of input pixels comprising electric charge converting means for converting an incident radiation into electric charges, electric charge storing means for storing the electric charges converted by the electric charge converting means, control means for controlling an electric field applied to the electric charge converting means, provided between the electric charge converting means and the electric charge storing means, and reading means for reading a signal based on the electric charges stored in the electric charge storing means;
an output line for outputting the electric charges read from the plurality of input pixels, connected to the plurality of input pixels; and
switching means for resetting the electric charge storing means.
Also, according to the present invention, there is provided a radiation image pickup device, comprising:
electric charge converting means for converting an incident radiation into electric charges;
electric charge storing means for storing the electric charges converted by the electric charge converting means;
control means for controlling an electric field applied to the electric charge converting means, provided between the electric charge converting means and the electric charge storing means; and
reading means for reading a signal based on a potential due to the electric charges stored in the electric charge storing means.
In the present invention, the type of radiation is not limited to x-rays, but may include electromagnetic waves such as xcex1-rays, xcex2-rays or xcex3-rays. However, the radiation is generally x-ray radiation.